New DRO on the Mill
Back in April I bought a Anilam Wizard 411 DRO (Digital Read Out). My old one broke when Jason accidentally moved the X-axis too far (which was totally my fault — I should have checked the stops and made sure it wouldn’t happen). It wasn’t all that bad, as it gave me a reason to add the Z axis for the knee. So, I was about to buy the Grizzly 3 axis DRO (literally had it ordered) when I got a 20% off email from ENCO. That made the totally sweet Anilam almost the same price, so I cancelled the order and bought the nice one from ENCO.
I setup the X and Y a long time ago, but I finally got around to doing the Z. I needed to mill a little spacer block for it, and get some new longer screws. Now it is all together and works GREAT!
Steel Bending Jigs
I’ve been working on creating a railing for the upstairs portion of my house. I wanted to create it out of steel and have some cool curves in it. I needed a bending jig, and after experimenting with wood I realized it wouldn’t withstand the forces I was exerting on it for the curves I wanted. So, I made one out of steel.
The jig is just clamped to my table.
It consists of some 3/16″ steel (I think) hand bent to the curve I wanted. The circular tube piece is to act as a strong resistance to the bend. I smoothed it out the outer edge with a file, and added another curl on top (welded in the center) to get the curve started:
Once the curve is started it can be dropped into the lower curve area and the curve finished:
Resulting curves:
Hopefully google will index this and help other people who are trying to figure out how to do some bends.
Some sites that inspired me:
http://www.mig-welding.co.uk/forum/showthread.php?t=7802
Bending Jig on Google books.
Hand done curves — great for art, but bad for consistent curves.
Recumbent Unicycle
Not a pretty beast, and not easy to ride. It took me thee weeks of practice before I could ride it, and only after that could I “sort of” ride it. No free mounting or anything crazy like that. The balance point is just crazy difficult compared to a regular unicycle.
Here’s a video of me riding it on 1/31/2010:
I still plan to “shine it up” and build a small backrest. I originally wanted a nice large backrest, but I decided that it would hinder the ride ability of it.
Here’s the building process, which went together really fast (it is a hack):
Cut up a bike and figure out roughly where I wanted things:
All trial and error, with some guessing:
Weld a seat together out of some old bike tubes:
Weld it all together and cover the seat:
Hmm…not too elegant of “steps”.
Adjustable Unicycle Handlebar
I was never happy with the last handlebar I made for my KH36 road unicycle. It attached underneath the base of my seat, and despite it being carbon fiber it still flexed quite a bit and I was afraid it would break. It also never felt quite right — I wanted it to be slightly lower, and slightly more forward. On my KH24 geared muni I have a handlebar that attaches to the seat post and has always felt great. Using the seat post wouldn’t work for my KH36, since I’m short and run the seat all the way as low as it can go when using 150mm cranks. In fact, I think I cut down the top tube on the KH36 frame a bit so I could get it extra low.
To work around this problem I made a new version that attaches to the frame and adjusts vertically when I use different cranks.
Here is a picture of the completed setup:
The individual pieces I made mainly from 22.2mm tubes (purchased from Aircraft Spruce) brazed together. The small piece at the bottom is an adapter to attach the brake in the direction that I like. I make the little seat post clamps on my lathe, and trim some fat off of them with the milling machine.
The base attaches to the frame:
The top T goes in, and can be adjusted up and down. I could also replace it if it ever breaks or doesn’t work the way I want.
After the brake is installed:
Top view. Notice that I run a set of bar ends backwards. I use these when riding rough terrain, or for climbing steep hills. I really prefer it to the typical front plastic handle found on nearly ever unicycle.
After I finished making it, I painted it with 2 coats of gray primer, 2 coats of black, and 2 clear coats.
Riding with it is a dream — it is exactly the handlebar I want. In theory I could also use this setup like a “V frame” unicycle, by tilting the seat forwards a lot and dropping the front handlebar post down all the way, but I haven’t tried that yet.
Building a Tandem Unicycle
My last post introducing my Tandem Unicycle originally started out with a step-by-step process of how I built it, but for some reason I lost the post. Here is how I made my tandem uni:
This idea is not my original idea. A few years ago at a “California Mountain Unicycle Weekend” a guy named LobbyBobster on the unicycle forums brought one and I gave it a try with Beau Hoover. Here’s a picture of the creator and their tandem, which looks much nicer than mine!
So, from seeing this uni two years ago and based loosely on this picture I set about making my own for no cost. I already had two old bikes that I got for free, so I was set to begin.
Materials:
* 2 Huffy Mountain Bikes
* 2 Unicycle Seats
Tools Used:
* Sawzall (with a bimetal blade)
* 4.5” angle grinder
* MIG welder
* Half round file
I took the wheels off of the old Huffy mountain bikes. One of the two rear wheels was going to become the main unicycle wheel, so I removed the rear cassette and saved the sprockets:
The intent was to weld the two rear halves of the bikes together, utilizing the rear triangle that already exists. I used the sawzall to cut the front half of the bike off:
(NOTE: in this picture I already had removed the seat post clamp for another project — you should leave it on if you are making your own tandem).
The rear triangle after I cut it free. Notice that the seat post tube is at an angle — I later cut it off and re-welded it vertical so it would be more “unicycle like”:
And the rear triangle of the other huffy after I cut it free:
I removed the main drive hub — one of the two has to be switched to the opposite side, and it worked well to remove both and re-grease everything after I welded it back together. Removing the hub was easy, even though I didn’t have the proper tool. I used a screw driver to get the reverse-threaded hub “bolt” out:
The next thing done was to cut off the vertical tube and cleanup the two holes left in the hub housing:
I then needed to weld the seat post tube vertical. I used a half-round file to cut a slight fish mouth out of the tube so it would fit nicely over the rounded hub housing. I then created a hokey setup to hold it vertical, testing the straightness with a square:
I tacked it, and welded it on. Note that the big holes are left:
I cut a piece out of one of the horizontal seat post tubes to use as a patch:
I tacked it on:
and then completed the weld. There is a patch on each side to cover up both holes. I then repeated the process for the other bike half. At this point I attached the two halves to the wheel to get a feel for it, and cut a top tube to size after making sure the bottom pieces were inline with each other:
The next thing I needed to do was to weld the two halves together. I prepped the steel and cut off the angled slot on one side:
I clamped them together, making sure the bottom pieces were in the same line with each other — that way, each seat post tube is parallel with the other.
After they were MIG welded together:
At this point I decided to weld the freewheel on the rear hub’s cassette so it wouldn’t freewheel. Note that the hub spindle still turns free.
The next part was to tack weld in the top tube in place, and cut some side tubes to fill in the frame:
For the other side doesn’t look as good. It turns out the two bikes were different frame sizes, and I wanted the top tube to be horizontal, so I had to do some funkiness to get it that way:
At this point I put the sprocket and hubs back together and stuck some unicycle seats in:
The only thing left was to weld on two sprockets in the wheel’s hub. I took two sprockets of the same size (one from each cassette), with about the same number of teeth as the smaller hub sprocket (in order to get a 1-1 gear ratio). I made a spacer by grinding off some of the teeth on one of the sprockets and used some of the plastic spacers that were left.
I then welded this to the hub (sorry, no picture).
At this point, the whole thing was put together with two chains, and I temporarily used a large sprocket in between two of the chains to keep the chain a little tighter:
Left todo is to create a chain tensioner, and to paint the thing.
corbin
Aerial Cube
I just finished another project: the Aerial Cube.
Louise and I saw the cube at a circus show last week, and I thought “Hey, I could make one of those!”, and Louise asked “Can you make me one of those?”. So, here it is!
The cube is made out of 1″ tubing that is 1/8″ thick. I bought it at a local metal place – “Sims Metals”.
I cut 45’s with my little Grizzly horizontal bandsaw:
And drilled+tapped some holes into a piece of steel to create a jig to hold the tubes at 90 degrees:
And then welded two separate squares together:
I then notched the four connecting pieces with a 1″ end mill so they would fit “fairly well”. I then MIG welded all the corners together, holding it together with a ratcheting wrap to keep it square. I then sanded it a bit…which got my hands a little dirty.
First Machining Project: Vise Stop
Every machinist needs a good vise stop. Here is mine, 100% completely made from raw steel, except for the bolts bolting it to the vise (which are too long — I need to buy new ones):
The knurled wheels use split collars to tighten the bolts down. The larger knurled ones work much better than the smaller ones (require less force to tighten the things down), and I may make some more larger ones.
So, how did this project come to finally being finished? I searched the net and found some great links on things people had done. I initially found A Vise Stop for the Kurt Vise on “CNC Cookbook” (excellent website!), which is based off of a post from CNC Zone. I decided to use the basic designs, but modify it slightly to avoid turning too many different sized rods, using the stock I had at hand, and also making it work for my Bridgeport vise. The Bridgeport vise has no tapped holes on the back, so I had to use some tapped holes on the top instead. I started up Sketchup and did some “quick” drawings. Feel free to download the file: Vise Stop and modify it, but here is a short picture of one of the two stops (they are different sizes):
I made split collars similar to how the guy on CNC Zone makes them, except I didn’t see a need to machine a small lip on them. Instead, I machined them to exact diameter and length, and then tapped it all the way through with 1/4-20 threads. I used a 1/4-20 brass thread that has nuts (and washers) on both sides. This held the split collar tight while I machined the half moon circle on it:
After I machined the circle in the collar, I split it by using the parting tool on the lathe and then drilled out one side’s threads (otherwise, it wouldn’t clamp tight!).
Overall, most the operations were simple, but it all taught me a lot: squaring up stock, machining it to size, drilling accurate holes, tapping, threading (with a die), knurling and turning between centers with a lathe dog.
Overall a great first “real” project (I have made other stuff, but mostly small things that I needed for other projects).
Milling machine tune up
My 1990 Enco Milling machine was starting to get quite a bit of shake at certain speeds. It has a variable speed head, and one of my friends, Bevan, recommended against getting the vari-speed, since they are sometimes prone to having trouble. But, I really do love being able to dial in the speed with the turn of a small wheel, and even though it was a pain to do, I tuned up the head and now it runs smooth again.
I took the head apart, carefully labeling stuff on my bench:
The main problem was a bad v-belt. The old one somehow managed to twist backwards, and was getting all chewed up and tossed a bunch of dust into the head cover:
Yikers, look at that mess of a belt:
Some more details of what a milling machine head looks like:
I also had to take the quill and quill housing off to fix a broken bolt that rotates the head left/right (we broke it when we moved the thing into my shop). It wasn’t too hard to replace, but it was a pain getting the quill back on (the thing is heavy!). Ultimately, I set the quill on a board and raised the knee up to get it into place, while Louise pushed the bolts in (no pictures of the process, sorry!). Getting the motor back on top of the head was a pain! The motor is very heavy, and I couldn’t get the variable speed disc off the motor, so I had to work the variable speed belt around it, which took some muscling and luck.
I also cleaned up some loose wires I noticed, and once the thing was back together it started purring like a happy kitten.
MIG welder
I picked up a used MIG welder a few weeks ago. The thing is totally cool; MIG is the way to go (Bronson was right!).
I already used it to weld a few little things; a custom grinder stand, and a little piece of steel to a nut. These are things that would have been a pain to do with the oxy-acet torch.
One ounce removed off KH Moment cranks
Joseph Campbell came over last weekend to ride trials. He was mentioning how heavy the KH cranks are, so I told him we could quickly mill out some material. I took a deep pocket out of the bank of them and removed one ounce form each crank. The cranks started out at about 11 oz and ended up at 10 oz each.
The chips on my mill:
UPDATE: How about I spell “ounce” and not “once”.